I too hate the fact that inherited runners that are allowed scored by bad middle relievers count towards the starter's ERA. I think they should adjust the ERA stat to account for the fact that inherited runners scoring are not entirely the fault of the pitcher that left them there. They should pro rate the earned run. IE. If the pitcher coming out leaves a runner on first and a reliever lets him score, the starter gets charged with .25 earned runs, and the reliever .75; if he left the runner on 2nd, they both get charged with half an earned run, etc.
That would make ERAs, especially of middle relievers a much more accurate indicator of performance. You wouldn't have worthless middle relievers like Ray "put Austin Kearns out for the season" King looking pretty with their sub-3.00 ERA that is so low only because he lets every inherited runner score.